The Bible attaches great significance to what we observe in the heavens, in the sun and moon and stars. Astronomical signs are God’s ‘bill-board’ for the world. They can occur on a regular basis, as in seasonal signs, or as unique events as a warning to the world. Either way, God’s timing of these celestial events is precise – there are appointed times and often they are associated with Israel’s appointed feasts (Num 9.2, Lev 23.2).
See also Israel’s Blood Moons
God puts signs in the heavens to help man order his year:
Then God said, ‘Let there be lights in the firmament of the heavens to divide the day from the night; and let them be for signs and seasons … then God made two great lights; the greater light to rule the day, and the lesser light to rule the night’ (Gen 1.14,16). He appointed the moon for seasons (Ps 104.19)
So, apart from providing light, the moon provides man with a calendar – God’s calendar (see sidebar).
The Bible records several unique astronomical events:
So the sun stood still, and the moon stopped, till the nation avenged itself on its enemies … the sun stopped in the middle of the sky and delayed going down about a full day (Joshua 10.13)
Some suggest that the text here is figurative and that the event did not actually take place. If the event really did take place, a number of scientific theories have been presented, link. A second unique astronomical event is recorded in Isaiah:
‘I will make the shadow cast by the sun go back the ten steps it has gone down on the stairway of Ahaz.’ So the sunlight went back the ten steps it had gone down (Isa 38.8)
It is claimed that this was no ordinary astronomical phenomenon in that it cannot be explained by any known astronomical law, link. So despite attempts to explain it by known laws, it remains a miracle of God, link. It was a sign from God to King Hezekiah that he would be healed and that he would live another 15 years. He did.
Heavenly signs are also given for guidance. When Jesus was born, wise men (Gk magi) from the east were guided to Bethlehem and asked:
Where is He who has been born King of the Jews? For we have seen His star in the East (Mat 2.2)
There is much debate about the astronomy behind this text. For example, it has been argued that the ‘star’ of Bethlehem was a supernova, a comet, or a triple conjunction of Jupiter and the star Regulus in the constellation Leo, link. A triple conjunction event did actually occur around the time of Jesus’ birth.
End Time Astronomical Signs
Heavenly signs are also given to warn mankind of God’s impending intervention in the world. When referring to the end of this present age, Jesus said:
there will be fearful sights and great signs from heaven … there will be signs in the sun, in the moon, and in the stars (Lk 21.11,25) … the sun will be darkened, and the moon will not give its light (Mat 24.29)
… the powers of the heavens will be shaken (Lk 21.26)
Here, Jesus is probably referring to the very last years of this age, when astronomical signs cause men’s hearts to fear for what is coming on the earth.
Comets and Meteors
Revelation 6.13 refers to “stars of heaven falling to earth, as a fig tree drops its figs”. Here, the Greek word for stars is astéres, link. Thayer’s Greek Lexicon suggests that this may refer to comets and if the earth passes through the tail of a comet we observe a meteor shower. A meteor (burning space rock smaller than an asteroid) that survives the earth’s atmosphere falls to earth as a meteorite. Even today, meteors are sometimes referred to as ‘falling stars’. The text is given in an end-time context and Jesus probably refers to the same event in Mark 13.25. He was referring to dramatic cosmic events as signs of His return to earth. Although Earth is bombarded with millions of tons of space material each day, Jesus implies that such signs will become more apparent just before His return.
Revelation 8.8,9 refers to “something like a great mountain burning with fire was throne into the sea … a third of the ships were destroyed”. This could be a biblical description of a future major asteroid impact in the sea, and, clearly, such an impact will generate a huge tsunami, link. Asteroid impact is certainly a reality. A Potentially Hazardous Asteroid (PHA) has the potential to make close approaches to the Earth and a size large enough to cause significant damage in the event of impact. The 1908 Tunguska asteroid (which nearly impacted) released energy equivalent to about 185 Hiroshima bombs, link. It was a timely warning. By January 2016 there were some 1,650 known PHAs, link. It only needs one to hit!
When the sixth seal in the Book of Revelation (Rev 6.12) is opened the sun is darkened and the moon turns blood-red. These unique astronomical signs are a prelude to the seven trumpets and the judgmental acts of God and they strike terror into the world’s great leaders as they realize Christ’s judgments are imminent. The arrogance of world leaders is halted as even the starry constellations are darkened (Isa 13.10). God says:
I will show wonders in the heavens … blood and fire and pillars of smoke. The sun shall be turned into darkness, and the moon into blood” (Joel 2.30,31)
Joel’s prophecy is given specifically in the context of regathered Israel, when God is pouring out His Spirit upon Israel’s sons and daughters at the very end of this age. At last, after severe persecution, war and signs from heaven, a remnant from Israel turn to their Messiah (Mashiach):
For in Mount Zion and in Jerusalem there shall be deliverance (salvation) (Joel 2.32)
Astronomy of Lunar Eclipses (Blood Moons)
Biblical references to a ‘blood-red moon’ may sometimes refer to a total lunar eclipse. A total eclipse of the moon occurs when the moon falls entirely within the shadow of the earth i.e. when it enters the Earth’s ‘umbra’. It is only possible when the Sun, Earth and Moon are aligned in a straight line and when there is a full moon (although this does not occur every full moon because the plane of the Moon’s orbital path around the Earth is inclined at an angle of 5° to the Earth’s orbital plane around the Sun). Alignment is only correct twice a year, link.
If we could look back at earth from within earth’s shadow we would see a red glow around the earth. These are earth’s sunsets and sunrises caused by atmospheric scattering of red light back to earth. This red light then illuminates the moon – hence the term blood-moon. A total lunar eclipse can last for hours as the moon passes slowly through the umbra, although its visibility varies depending upon date and time (usually half of the earth at a time). For example, the 15 April 2014 eclipse was best seen in the Western Hemisphere, whilst the 8 October 2014 eclipse was best seen from the Pacific Ocean.
When four consecutive lunar eclipses are all total eclipses, the group is known as a tetrad. During the 21st century there will be 85 total lunar eclipses and also 8 tetrads occurring in 2003/4, 2014/15, 2032/33, 2043/44, 2050/51, 2061/62, 2072/73, and 2090/91, link.
Astronomy of Blood Moons: The tetrad of 2014-2015
Biblical Blood Moons
Having summarized the astronomy of blood moons, it is necessary to ‘connect the dots’ with what the Bible says on the subject. As already mentioned, the Bible says that at the end of this age there will be warning signs in the heavens, and these include blood-red moons!
And when he had opened the sixth seal … the sun became black as sackcloth and the moon became as blood … and the stars of heaven fell to the earth … then the sky receded as a scroll when it is rolled up … (Rev 6.12)
This may be a reference to solar and lunar eclipses in the last few years of this age (Joel 2.30,31), although astronomically, these cannot be simultaneous solar and lunar eclipses. If they are eclipses, they are just part of dramatic, awe-inspiring and fearful celestial sights as men realize the coming ‘wrath of the Lamb’ (Rev 6.16).